Electrical Code…
The conductive path(s) that provides a ground-fault current path and connects normally non-current-carrying metal parts of equipment together and to the system grounded conductor or to the grounding electrode conductor, or both.
Informational Note No. 1: It is recognized that the equipment grounding conductor also performs bonding.
Informational Note No. 2: See National Electrical Code® Section 250.118 for a list of acceptable equipment grounding conductors.
(National Electrical Code® 100-1)